Beginner .308 reloading - where to go next

[whoami-72]

Alright guys. Still trying to get back into reloading and I'm not sure where to go next.....

Setup: seekins ph2 with 24" barrel. Norma brass staball match powder. Cci 200 primers. I got a USA made RCBS 505 recently. Hornady dies. Magnetospeed sporter chrono

My original goal was to copy cat the superformance .308 150 gr cx bullets.

Reloads so far:
I randomly loaded up some 150gr sst's at 49grains but I was using a Lee safety scale and got frustrated so my powder weighs weren't the best. They shot a 1.5 moa group at 2950 fps.

Today I decided to do a speed and pressure test thinking it would show me pressure signs and give me an idea of what speeds to expect. Data is below.

I also varied the seating depth on the cx bullets because I was trying to mimic the factory loads but a 0.05" jump is when I load to 2.80". Also, I rounded my seating depths to the nearest hundredth because my hornady dies are usually +or- .04"

Factory hornady superformance .308 win 150 gr. COAL is roughly 2.74 and speed was 2860.

Reloads below:
2.80 COAL and CX bullets
Powder weight - speed - notes
46.0 gr - 2908 slightly hard bolt lift
47.0 grC - 2898 slightly hard bolt lift
48.0 grC ‐ 2940 same bolt lift
49.0 grC - error hard bolt lift

2.74 COAL and cx bullets
44.0 gr - 2738
45.0 gr - 2757
46.0C gr - 2796

I also tested TTSX's but I struggled with loading them because they would shave off little pieces of copper while loading even though I chamfered the case mouths.

2.80 COAL and TTSX
45.5 gr - 2784
46.0 gr - 2815
46.5 gr - 2816
47.0 gr C - 2849

I did also load up some extra SST's
2.80" coal
47.0 gr - 2886
47.5 gr - 2868
48.0 gr - 2914
48.5 gr - 2926
49.0 gr -2951

2.733" coal
47.0 gr - 2888
47.5 gr - 2869 chrono slid
48.0 gr - 2915 beginning of slight bolt lift issues
48.5 gr C - 2939 bolt lift
49.0 gr C - 2979 primer ever so slightly starting to push out but only noticeable with caliper.

So, where do I go from here?

If I follow the hornady podcast method..... back 1 grain off of the loads that showed pressure and load 30 rounds. If it doesn't shoot, try something else. Seating depth be damned.

Erik Cortina method said to pick a speed I want and then tune groups with seating depth. What speed do I pick?

Case capacity method (mentioned by a hornady podcast guess). Find a load where the powder fills up most of the case capacity or slightly compresses and shoot it.

My prior method when I loaded a few years ago was to just load 3 shot groups ever .2 grains until I found an area that generally grouped well and then load 10 round groups to finalize my powder charge. Always loaded to mag length. Never had a chrono back then so it was always group based.

So, what do you guys think?

My gut says to try 2 different groups:
pick a load 1 grain from pressure signs and load 10 rounds. If it groups well then awesome. If decent, try tuning with seating depth. If terrible, move on.

In the next batch, find the loads that are slightly compressed with the 2.8" coal but arent showing pressure and load a group in hopes the filled case capacity would have good/consistent speeds.

 

[mt100gr.]

If you're wanting to copy the Superformance load, I'd start with Superformance powder....

Given what you tried, I'd dump the barrel mounted chrono and load up 10-20 SSTs (better than a mono) at 47.5 grs with either seating depth and see what the group looks like. The velocity will be what it'll be, I'd look for accuracy/precision/consistency first.

 

[MtnSquach]

What do you plan to use the rifle/load for? If hunting you want to pick the bullet that works for you, and a velocity that works for the game/distance you plan to use it for. I’m not a match/prs guy, but I would assume velocity is less important for that as long as the load shoots good groups at the distance you want to shoot.

Recently I have also been also going down the Hornaday podcasts rabbit holes. Their information makes sense to me. The bigger the test groups the better information you will obtain about the load.

Last week I worked up a load for my 300 PRC and used the fastest load without pressure signs. I loaded 10 more and found good sd/es and ok groups. I played with seating depths in .005” increments from .010” off to .035” off and saw no change in sd/es or groups. I just went back to .025” off the lands and it’s pretty consistent there.

I just loaded a 3gr ladder in .5gr increments for my 6.5 PRC to find pressure and check velocities. 7 of the 9 shots were 3/4” at 100 yards (1 I pulled and 1 had a pressure/velocity spike, not sure why, it wasn’t the largest powder charge ). If I had used the same point of impact for all of the shots the group would have been less than 3/4” eventhough the velocity increased almost 200fps with the increasing powder charges. It seems like my rifle likes that bullet/powder combo because the accuracy was great across the board even though the group es was like 177fps.

I’ve only watched a few videos with Erik Cortina but when he talks about accuracy he is talking about a 1/4moa group. I’m sure at that point you can squeeze out a little more accuracy with seating depths. But that beyond my skill and my rifle’s capabilities. But I didn’t not notice a huge difference in accuracy for my load/rifle.

It seems like if you find the right bullet/ powder combo you rifle likes you will have a great shooting load. If your set in that bullet and it won’t group as small as you want with a 10-20 group (under visible pressure signs) I’d change the powder and see if accuracy improves.

 

[MtnSquach]

If you're wanting to copy the Superformance load, I'd start with Superformance powder....

Given what you tried, I'd dump the barrel mounted chrono and load up 10-20 SSTs (better than a mono) at 47.5 grs with either seating depth and see what the group looks like. The velocity will be what it'll be, I'd look for accuracy/precision/consistency first.

I believe the powder used in factory ammo is not the same as what they sell in the Superformance powder.

 

[whoami-72]

If you're wanting to copy the Superformance load, I'd start with Superformance powder....

Given what you tried, I'd dump the barrel mounted chrono and load up 10-20 SSTs (better than a mono) at 47.5 grs with either seating depth and see what the group looks like. The velocity will be what it'll be, I'd look for accuracy/precision/consistency first.

Fair points all around.

Superformance doesn't have load data for .308 in hornadys book or on hodgdon's website so thats why I didn't try it.

I probably should've mentioned. Unless the SST's shoot blazing fast and/or have sub .75moa 5 shot groups. I don't have a ton of interest in loading them. My goal with reloading was to have a copper load. The factory Norma tip strike shoots phenomenal out of this gun and are pretty close to the SST's in terms of performance. I only gave them a shot because I've had a box of SST's sitting in my drawer for 5 years and figured they'd be cheaper to learn on then the coppers. That being said, I'll probably try it anyway cause I have to get rid of the bullets at some point anyway.

 

[mt100gr.]

I believe the powder used in factory ammo is not the same as what they sell in the Superformance powder.

Certainly possible!

 

[Pescetism]

If you're wanting to copy the Superformance load, I'd start with Superformance powder....

@MtnSquach is correct; Superformance reloading powder isn't the same powder as what's used in Superformance factory ammo.

Otherwise, I agree with the chrono and SST comments. But if you're wanting to stay with the CXs I'd drop down to 44.5 or 45.0 and see if you're still getting hard bolt lift. If not, then load 10 rds at 2.8 and see how they group.

 

[MtnSquach]

Fair points all around.

Superformance doesn't have load data for .308 in hornadys book or on hodgdon's website so thats why I didn't try it.

I probably should've mentioned. Unless the SST's shoot blazing fast and/or have sub .75moa 5 shot groups. I don't have a ton of interest in loading them. My goal with reloading was to have a copper load. The factory Norma tip strike shoots phenomenal out of this gun and are pretty close to the SST's in terms of performance. I only gave them a shot because I've had a box of SST's sitting in my drawer for 5 years and figured they'd be cheaper to learn on then the coppers. That being said, I'll probably try it anyway cause I have to get rid of the bullets at some point anyway.

It’s been like 10+ years since I have loaded .308 but I had pretty good results with IMR4064 and Barns TTSX. At that time is was a great powder for the .308, not sure how it stacks up to these modern powders. If you don’t get the results you like with the Staball I’d try another powder. I’m sure there is several threads on Rokslide and other forums with load data for the SST’s and TTSX’s.

 

[whoami-72]

What do you plan to use the rifle/load for? If hunting you want to pick the bullet that works for you, and a velocity that works for the game/distance you plan to use it for. I’m not a match/prs guy, but I would assume velocity is less important for that as long as the load shoots good groups at the distance you want to shoot.

Recently I have also been also going down the Hornaday podcasts rabbit holes. Their information makes sense to me. The bigger the test groups the better information you will obtain about the load.

Last week I worked up a load for my 300 PRC and used the fastest load without pressure signs. I loaded 10 more and found good sd/es and ok groups. I played with seating depths in .005” increments from .010” off to .035” off and saw no change in sd/es or groups. I just went back to .025” off the lands and it’s pretty consistent there.

I just loaded a 3gr ladder in .5gr increments for my 6.5 PRC to find pressure and check velocities. 7 of the 9 shots were 3/4” at 100 yards (1 I pulled and 1 had a pressure/velocity spike, not sure why, it wasn’t the largest powder charge ). If I had used the same point of impact for all of the shots the group would have been less than 3/4” eventhough the velocity increased almost 200fps with the increasing powder charges. It seems like my rifle likes that bullet/powder combo because the accuracy was great across the board even though the group es was like 177fps.

I’ve only watched a few videos with Erik Cortina but when he talks about accuracy he is talking about a 1/4moa group. I’m sure at that point you can squeeze out a little more accuracy with seating depths. But that beyond my skill and my rifle’s capabilities. But I didn’t not notice a huge difference in accuracy for my load/rifle.

It seems like if you find the right bullet/ powder combo you rifle likes you will have a great shooting load. If your set in that bullet and it won’t group as small as you want with a 10-20 group (under visible pressure signs) I’d change the powder and see if accuracy improves.

My goal was hunting. The factory Norma tip strike has great accuracy for me but doesn't do great in wind. When I was shooting the copper superformance factory loads I was getting a trajectory similar to a .270 so I was thinking it would be nice to have a fast copper load in case I decide to hunt desert elk in November again this year and the winds are super strong like they normally are.

 

[Caseknife]

If you want to shoot monos, try the 137 Hammer Hunter with 8208XBR. My Howa Superlite shoots them at 3100fps.